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Topic: Bench Power Supply (Read 327 times) previous topic - next topic


Nov 17, 2014, 01:41 am Last Edit: Nov 17, 2014, 01:44 am by Swmitchell
Hi Everyone!
I have been reading these forums for AGES and rarely have I need to ask for help (someone has been there before). So... Here I go.

Someone has given me an old PA. It has an AWESOME transformer in it. It's got 2 windings. 100v and a 75v... but it's so heavy! I reckon it will pull 1500W NPZ.

My first thought was to re-wind it and bring that second coil/tap/winding down to about 40v and use 2 x  2n3055 with 2 of those buck variable dc-dc converters to give 2 variable output rails... but this is really a copy of the first bench power supply I made with a bigger re-wound transformer.

I'm looking at the 2n3773 series power transistors... and wondering if I have to re-wind my transformer. How would I go about supplying a 40/50v variable reference voltage to the base it?

I've got a spare descent heat sink... I've got a spare descent regulator and some appropriate caps for a bigger project already...

I have no project in mind that will use more than 30v currently.
I dont really want to rewind this if I dont have to... It's such a great transformer.

Perhaps there is a better way I could use these bits. What would everyone do?


It's such a great transformer.
I had lots of similar transformers kicking around but sent them to recycle.
I am now using DC to DC converts that are prevalent on eBay now.
Light, small and with current protection.

There are zener diodes to set voltages, you can even put two or more in series to get the voltage you need.
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